Security is an important requirement in many printing applications. In situations such as official or government document printing, event ticket printing, financial instrument printing and the like, many printed materials must be protected against copying, forging and/or counterfeiting.
In some situations, document creators may wish to encode a security mark in a document in a way that is invisible to the human eye, but which can be detected by optical character recognition (OCR) systems. An example is printing of a hospital security bracelet, where it may not be desirable to make personal information visible. However, existing methods of encoding security marks onto printed materials exhibit various technical limitations. Invisible inks can be used, but they are expensive to apply and can degrade over time. In addition, the technical capabilities of various OCR systems can vary, so not all printed security marks can be read by various OCR systems.
This document describes methods and systems for creating and using a document with a security mark that addresses at least some of the problems described above, and/or other problems.